Internal-combustion engine



March 27, 1945. D. CAMPBELL INTERNAL-COMBUSTION ENGINE Filed NOV. 1, 1943 Patented Mar. 27, 1945 Y NIT D- TEN -ponie I This invention relates to improvements. inimt'ernal combustion engin'es-r ore-the. four-cycle reciprocating type and has foritsprincipak'obiect an internal combustion engine of thereciprocatr ing piston type' having a compressible connecting rod whereby a portion of the initial'poweroitthe explosion is stored in the compressible connecting rod and "then" imparted to the movingrpaxtsto' drive the crank shaft. I i I A furtherobjectoi the presentinventioir'isz the provision of an internalcombustion enginehav-y ing a compressible connectinglrodcwherehy the piston will travel fartherronf-the' exhaustastroke than it does onthe compression. stroke; thereby exhausting a larger percentage .of thespentigasel than is normally obtainablenfrom the use; of the fixed connecting rod. Another object of this invehtionisthaproz: vision. of an internal combustion engine having resilientlmeans operable'tosmooth out the power stroke by distributing itrmore; uniformly-tactile power stroke. 1;.

I Still further objects of. this inventimaincinde means whereby the motor ..vibrationyis: greatly reduced and the pounding Ofithe bearingsis stantially eliminated since the sharn impactaor the explosion is absorbed: by the resilient-on pressible connecting -rod'..i:--.-

Other objects will appear during the course of the specification wherein reference is had to the drawing in which: m

Figure '1 is an elevational view partly broken away of an internal combustion engine embodying this invention. I

Fig. 2 is an enlarged elevational view partly in section of the compressible connecting rod including a portion of the-associated parts.

Fig. 3 is a sectional view taken on line III-III of Fig. 2.

Fig. 4 is a sectional view taken on line IVIV of Fig. 2. I

Throughout theseveral views like reference characters refer to similar parts, and the numeral I0 designates a crank case of an internal combustion engine in which is rotatably mounted a crank (shaft 12 of the usual type wherein crank offsets M with crank pin I6 are providedfor each cylinder and are relatively offset circumferentially to present a substantially even flow of power to said crank shaft.

A cylinder block l8 of any standard make is carried by the crank case 10 and is provided with a cylinder in which is reciprocablymounted a piston 22. Conventional inlet valve 24 and exhaust valve 26 are provided to admit the fuel gas and exhaustthe spent gases. Spark plug 28' is .timed in the usual manner toignite thefuel gas at, the-end of the compression stroke. The connecting rod 30 comprises a member 32 having a head 34, which clampingly engages the piston pin 36,.and also having a stem 38-.which extends into the cylindrical recess 40 formed in the connecting, rod member-.42. having a head which. is .operatively connected with the crank pin :bym'eansof-the bearing cap: 46 and screws 51).; The cylindrical .recess Mthas an enlarged portion 52 adjacent its outer enduto form an abutment 54. Av cylindrical disc .55 is fitted into the enlarged portion 52 of the cylinder tox'rest onabutment 54-.and issecured in position. by a set screw 58. 'Stem- 3&=is slidably mounted in disc 56. andiis: threaded at its outer end at E0 to reeeive aguide piston 62. Setscrew 64 serves to prevent accidental. unscrewing of the piston. Normally. disc56 and guide piston 62. are spaced apart-a1 sufiicien-t distance to receivea coil spring (it therebetween, This coil. spring; is inserted under compression and serves to urge piston 62 further into the cylindrical recess-All; I

Ahelical spring 68 encompasses stern 381with itsone end resting against head 322and the other end thereof" resting against 'the'bentering disc 5&4 Itxwill be noted that'th'elower portion of helical spring. 681s positioned in the upper-portion. ofthe recess 52., Spring 68 as shown in Fig.

2, is substantially at its normallengthqand. is adapted to be compressed to such a degree that the adjacent convolutions will contact each other, thereby providing a limit to the shortening of the connecting rod. The coil spring 66 is relatively light but always exerts a sufllcient force on guide piston 62 to maintain the head 34 against the spring 68 to preclude all lost motion of the parts. I

Any conventional lubricating system, such as the one shown, wherein the oil is delivered to the crank pin by an oil scoop 10 through hole 12, thence through hole 14 to the cylinder recess 40, thence by way of a center opening 16 formed-in stem 38 to the piston pin 36 may be used. The

reciprocating action of the guide pistontz as when the connecting rod is in substantial align- I ment with the center of the piston pin and the center of the crank shaft. The crank shaft rotates in the direction indicated by the arrow.

and is usually traveling at a high rate of speed, thus producing a peak pressure against the piston when the connecting rod i substantially positioned as shown in Fig. 1. This explosion stroke exerts a driving force against the crank pin I6 and at the same time compresses the helical spring 68. As the piston 22 moves fartherdownwardly in cylinder 20 and the explosion pressure is reduced, the stored up energy in spring 68 will be imparted to the crank pin as the connecting rod returns to its normal position. This application of the power stroke makes it possible 'toapply th driving power to the crank shaft when 13811511318 spring normally urged to the contracted position by a relatively weak spring when operatively interconnecting said piston and crank shaft.

4,. man engine of the class described having the leverage relation of the parts is substantially" at its maximum.

On the exhaust stroke, when valve 26 is open and there is very little head pressure, the piston will travel farther in the cylinder than it will I during the compression stroke when all valves are closed and the fuel gases are highly com pressed. This action of the piston is made possible by the helical spring 68 and has the advantage of discharging a larger percentage of the spent gases than could be obtained by the use of the standard connecting rod. This spring action also absorbs and stores up to a considerable degree, the sharp explosive force of the fuel explosion, thus reducing the wear of they-engine bearings, reducing the engine vibration and producing a much smoother action of the power stroke.

'reciprocable piston and a rotatable crankshaft,

a longitudinally compressible connecting rod disposedbetween said piston and crank shaft and operatively connecting said piston .and crank shaft and resilient means to limit extension of said connecting rod.

arecipro'cable piston and a rotatable crank shaft,

anextensibleconnecting rod having one of its end portions slidably mounted in a recess in the other end portion of said connecting rod, a spring mounted on said rod to urge said rod portions in opposite directions, and a spring mounted on said rod piston toconstantly urge said connecting rod partsto the contracted position.

5.-In an engine of the class described having a reciprocable. piston and a rotatable crank shaft, aniextensible;connecting rod having one of its endportions slidably mounted in a recess formed in the other end portion of said connecting rod, a springimountedon said rod to urge said rod portions in opposite directions, and resilient means tolimit the relative outward movement of said' connecting rod portions.

6.--In an 'engineof the class describedhaving a-reciprocable piston and a rotatable crank shaft. an extensible connecting rod having resilient means whereby it may be forcefully extended or shortenedfromdts normal position operatively connecting said piston and crank shaft whereby the piston is permitted to travel different lengths of stroke during the operation of theengine.

7. In an internal combustion engine having a reciprocating. piston and rotatable crank shaft, an extensible connecting rod interconnecting saidpiston and crank shaft and having resilient means whereby it is normally maintained at a predetermined extended length, and resilient means operable to limit its extension.

IVAN D. CAMPBELL. 

